Metal pop-out stabilizing tail for small bombs



March 9, 1954 J. A. PECK METAL POP-OUT STABILIZING TAILS FOR SMALL BOMBS 2 Sheets-Sheet 1 Filed May 11. 1951 F ig. I.

6 INVENTOR.

Joseph A. Peek (deceased) 8y A/l'fl .51 Pack (Erecutor) ATTORNEY J. A. PECK Match 9, 1954 ME'I AL POP-OUT STABILIZING TAILS FOR SMALL BOMBS Filed May 11, 1951 2 Sheets-Sheet 2 INVENTOR. Joseph A. Pack (deceased) 0! Allen 3. P805 (Executor) By maven/ Er Patented Mar. 9, 1954 UNITED STATES PATENT OFFICE METAL POP-OUT STABILIZIN G TAIL FIOR,

. SMALL BOMBS Application May 11, 1951, Serial No. 225,802

8 Claims.

This invention relates to a telescoping metal tail for a small cluster bomb. More specifically, it refers to a metal tail adapted to be attached to a small bomb, which tail has folding vanes which can be nested within the telescoping tail body.

In the construction of small bombs, the tail surfaces necessary to stabilize the bomb and give it the required stability in flight are relatively large. uniform in shape with respect to the bomb body and since small bombs of this type are usually clustered, the problem of providing some form of folding or telescoping tail surfaces is almost a necessity in the interests of economy of space.

It is the object of this invention to provide a compact tail assembly for a small bomb. It is a further object to provide tail surfaces that will fold into a diameter no greater than the diameter of the bomb. A still further object is to provide folding tail surfaces that telescope into a length less than that of the extended open surfaces. Yet another object is to provide tail surfaces that can be folded and telescoped in such a manner that the bomb lends itself readily to clustering. More specifically, an object is to provide folding tail surfaces that will give the bomb a high rotational speed and at the same time keep the terminal velocity at a reasonable value. The latter function becomes important in certain types of bombs where it is desired to preserve the bomb casing reasonably intact when the bomb strikes.

These and other objects are accomplished according to the herein-described invention which broadly comprises a longitudinally telescoping tail section for a small bomb wherein the extended surfaces are folded within the circumference of the tail section.

In the drawings, Fig. 1 shows the telescoped tail on a bomb. Fig. 2 is a top view of the same. Fig. 3 is a sectional view of the folded tail at 3-3 (Fig. 2). Fig. 4 is a sectional view at 4-4 (Fig. 3). Fig. 5 shows the extended tail together with the released gasket, cover, cover strap and strap lock. Fig. 6 is a sectional view of the extended tail. Fig. '7 is a top view of the extended tail. Figs. 8 and 9 are perspective views of a tail vane and the cover strap and lock respectively.

More specifically, i is the bottom telescoping section of the housing, 2 is the intermediate section of the housing, 3 is the tail vane section of the housing, 4 is the bottom section ejector spring rest, 5 is the ejector spring, 6 is the threaded base ring for attaching the tail section to the Moreover, such tail surfaces are nonbomb body, is the square shoulder joint between the bottom and intermediate sections, 8 is the square shoulder joint between the intermediate and tail vane sections, 9 is the vane sec tion baffle, I9 is the vane section base ring, I is the vane pivot shaft, I2 is the folding tail vane, i3 is the tail vane spring, I4 is the tail vane section cap, [5 is the tail vane stop, it is the tail vane drag surface, i1 is the tail vane section cover, I8 is the tail cover gasket, I9 is the cover strap, 20 is the cover strap hook and 2| is the cover strap lock.

The respective parts are assembled as shown in sectional Figs. 3 and 6. The intermediate and tail vane sections are passed through the base section in that order and the ejector spring is inserted and positioned against the ejector spring rest A. The tail vane section, 3 is formed of the base ring Hi and section cap M which are positioned apart by the 3 vane pivot shafts H. The baffle 9 is positioned within the diameter formed by the 3 vane pivot shafts and is attached to the base ring Hi. The three tail vanes are attached, one to each tail vane shaft by partially folding the sheet metal round the shafts, the biasing tail vane spring having first been placed on the shaft as shown. The tail vane stop I5 is positioned to engage the flange of the section cap I4.

Commencing with the tail section in the closed position shown in Fig. l, the threads 6 of the bottom section engage similar external threads on the bomb body and cover strap l9 and cover strap lock 2! are in place. In this condition, the telescoped tail occupies a minimum of space and is essentially the same diameter as the bomb body. In this condition therefore the assembly adapts itself especially well to nesting. The nested bombs are laid side by side in such a manner that the cover strap lock of each bomb contacts at least one other bomb in the nest. This contact prevents the opening of the telescoping tails while the bombs are nested.

Immediately upon release, the bombs separate sufficiently to permit the cover strap lock 2| to tilt away from the bomb body. This movement is effectively assisted by the fact that the lock is biased away from the bomb body by means of a split spring section on strap lock 2| and the tension of the ejector spring 5 also tends to push the cover It on the housing and therefore to lift both strap I9 and strap lock 2|.

Once the strap lock 2| moves away from the bomb body, the onrushing air past the falling bomb catches the bottom of the strap lock and assists in flipping it up and off, carrying cover strap I9 with it. Cover I'I falls off simultaneously. At this point, ejector spring is free to open the telescoping section which instantly extends up to the stops at square shoulders I and 8. Simultaneously, the moment the tail vane section 3 extends free of intermediate section 2, the vanes I2 will open, due to the biasing action of springs I3. The vanes I2 move back under the tension of springs I3 as Well as the action of the air on drag surfaces I6 until the tail vane stop I5 engages the flange on the cap I4. The bomb tail is now in a fully extended to open position and effectively stabilizes the falling bomb. The lateral drag surfaces I6 serve to exert a rotational force on the bomb and also serve to hold the terminal velocity to a reasonable value.

In experimental tests on the type of bomb and tail unit illustrated, the bomb attained a rotative speed of approximately 3500 R..P. M. in a fall of 300 feet. The terminal velocity of this same bomb is from 350 to 375 feet per second.

In the construction of a tail assembly as shown it has been found desirable to use vanes of a size that will occupy about of the circumference of the tail section. This limits the number of vanes to 3, which is adequate. If a larger number of vanes are used their extended length will necessarily be less and their combined eifectiveness in lending stability to the bomb is less.

It has also been found desirable to use the baffle 9 in the tail vane section for it greatly improves the aerodynamics of the bomb. In the structure shown there are a total of 2 telescoping sections plus the tail vane section. It is obviously possible to insert additional telescoping sections if further tail length is desired. It has been found experimentally, however, that adequate stability may be had with the sections shown so that the complication incident to the addition of further sections was not considered advisable.

In telescoping the tail assembly to prepare it for stacking. the reverse of the steps recited in the opening thereof must necessarily take place. That is, the vanes are first folded whereupon the tail vane section is pushed down against the ejector spring until the entire unit is collapsed as shown in Fig. 3. The cover, cover strap and strap lock are then applied. The latter may be held in place by a piece of adhesive tape until the bombs can be nested when the adhesive is removed.

What is claimed is:

1. A telescoping tail for a small cluster bomb which comprises a hollow cylindrical base section, cylindrical coaxial sections of progressively lesser diameter capable of nesting within the base section, circumferential stops on the various sections to limit their extension, a cylindrical tail vane section positioned within the nested coaxial sections and having a circumferential stop thereon like the said coaxial sections and having vertically pivoted vanes disposed around the periphery of said section, said vanes being spring biased to a radially extended position and being capable of being folded within the diameter of said section, an internal spiral spring within the cylindrical sections to urge the coaxial sections to an extended position.

2. A structure according to claim 1 wherein the circumferential stops comprise square shoulder joints at the ends of the respective sections.

3. A structure according to claim 2 wherein there are three pivoted vanes disposed apart on the outside edge of the vane section.

4. A structure according to claim 3 wherein a cylindrical baflle is disposed within the tail vane section.

5. A structure according to claim 4 wherein the pivoted vanes have laterally extending drag surfaces which give a rotational impulse to the bomb.

6. A structure according to claim 5 wherein the vanes have stops for preventing their extension beyond a predetermined point.

7. A structure according to claim 6 wherein the base section has internal threads for attachment to the bomb body.

8. A structure according to claim 7 incorporating a cover and lock adapted to hold the assembly in a closed position while nested.

ALLEN S. PECK, Executor of the estate of Joseph A. Peck, de-

ceased.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,879,840 Brandt Sept. 2'7, 1932 1,890,175 Brandt Dec. 6, 1932 2,421,752 Jones June 10, 1947 2,426,239 Renner Aug. 26, 1947 

